Manual Deep Anterior Lamellar Keratoplasty Research Articles

Rediscovering a valuable manual Deep Anterior Lamellar Keratoplasty (DALK) technique: Outcomes of 42 "Peeling-off" DALK.

Residual bed thickness in DALK should be less than 80μm to provide optimal visual outcomes. "Peeling-off" is a manual DALK technique, which separates the anterior stroma by pulling the deep stromal lamellae following the plane of their lowest adhesion, which is usually very deep. The purpose of this study is to measure the residual bed thickness achievable with this technique. Retrospective case series of "Peeling-off" DALK cases performed between January 2014 and January 2021 with at least 1 year of follow-up. Indications for DALK, intraoperative and postoperative complications, residual recipient bed thickness at 1 day and at 1 month after surgery, and postoperative best corrected visual acuity (BCVA) at 1 year of follow up were evaluated. 42 eyes (42 patients) underwent DALK performed with "Peeling-off" technique. Indications for surgery were keratoconus in 33 eyes and stromal scar in 9 eyes. "Peeling-off" technique was used as a rescue approach to perform a DALK after a failed Big-Bubble in all cases, and also failed Air-Visco-Bubble in some cases. No intraoperative and postoperative complications were recorded. Residual recipient bed thickness was deep and regular, measuring 42 microns at 1 day postoperative (range 21-65 microns) and 23 microns (range 17-26 microns) at 1 month postoperative. Mean postoperative BCVA at 1 year of follow up was 0.18 logMAR ± 0.09. "Peeling-off" DALK is a valuable manual technique that achieves a deep stromal plane with optimal visual outcomes.

Corneal aberrations, densitometry on scheimpflug imaging, and visual acuity after deep anterior lamellar keratoplasty.

To evaluate visual acuity, corneal aberrations, and densitometry post deep anterior lamellar keratoplasty (DALK). Twenty-five eyes of 25 patients who underwent DALK for corneal stromal diseases with normal endothelium were enrolled in a prospective interventional study. Evaluation for corneal aberrations and densitometry postoperatively was performed using Scheimpflug imaging at 6 months. Anterior Segment Optical Coherence Tomography (ASOCT) was done for host-graft morphology. Correlation analysis of postoperative best-corrected visual acuity with corneal aberrations and corneal densitometry (CD) was performed. Big bubble deep anterior lamellar keratoplasty (BB-DALK) was successful in 18 patients, while 7 eyes underwent manual dissection due to failed BB (Big Bubble) technique. The mean BSCVA was 1.35 ± 0.46 logMAR units pre-operatively which improved to 0.36 ± 0.19 logMAR units post DALK at 6 months (P < 0.001). The mean Root Mean Square (RMS) (μm) of the magnitude of total corneal aberrations, HOA and LOA from central 6mm zone of cornea were 14.6 ± 9.2, 4.7 ± 2.9, and 13.8 ± 8.8, respectively. The mean anterior (120μm), central and posterior corneal (60μm) densitometry in 0-2mm zone were 25.8 ± 7.7 GSU, 18.7 ± 4.16 GSU and 10.09 ± 3.9 GSU respectively. A statistically significant correlation of postoperative residual stromal bed thickness, total corneal HOA, LOA, total corneal aberrations, HOA front and posterior corneal densitometry (0-2mm zone) with postoperative BSCVA was found. Though there is a significant improvement in BSCVA after DALK, the quality of vision in terms of aberrometry and densitometry is suboptimal, especially in cases undergoing manual DALK compared to those undergoing big bubble formation.

Femtosecond laser-assisted deep anterior lamellar keratoplasty: A safer option in keratoconus surgery.

To evaluate postoperative safety of femtosecond laser deep anterior lamellar keratoplasty performed with an innovative anvil profile in keratoconus patients. This is a single-center, retrospective cohort study. We reviewed medical records of 89 keratoconus patients that underwent femtosecond laser deep anterior lamellar keratoplasty surgery (46 eyes) and manual deep anterior lamellar keratoplasty (47 eyes). Inclusion criteria required: age > 18 years old, best-corrected visual acuity < 0.3 LogMAR, continuous suture of the graft, postoperative immunomodulant regimen with dexamethasone 0.1% for 6 months and at least 12 months follow-up. Previous eye surgery, hydrops, and other ocular disease were excluded. The main outcome measures were postoperative events: rejections, persistent epithelial defects, and graft failures. During the follow-up (20 ± 6 months) graft rejection was diagnosed in 0 of femtosecond laser deep anterior lamellar keratoplasty versus 6 (17%) of manual deep anterior lamellar keratoplasty [p 0.027], persistent epithelial defect in 0 of femtosecond laser deep anterior lamellar keratoplasty versus in 4 (11%) of manual deep anterior lamellar keratoplasty [p 0.048] and graft failure occurred in 4 (11%) of manual deep anterior lamellar keratoplasty. The best-corrected visual acuity, after removal of sutures, was better in the femtosecond laser deep anterior lamellar keratoplasty group 0.09 ± 0.08 LogMAR versus 0.16 ± 0.13 LogMAR in manual deep anterior lamellar keratoplasty [p 0.035] group although refractive spherical equivalent and cylinder, topographic average keratometry and cylinder were similar. Anvil-shaped femtosecond laser deep anterior lamellar keratoplasty in keratoconus surgery increases safety and readiness of recovery, decreasing the incidence of corneal rejection, epithelial defects, graft failures, and producing better best-corrected visual acuity after removal of sutures.

Deep anterior lamellar keratoplasty for corneal penetrating wounds.

To report our surgical experience of deep anterior lamellar keratoplasty (DALK) performed in eyes with scarring resulting from a corneal penetrating wound without tissue loss. Case series of three eyes of three patients that underwent DALK for poor vision due to a scar resulting from a previous corneal penetrating wound. Surgery was performed at least 1 year after the initial injury. Manual dissection technique was used in all cases. Preoperative and postoperative best correct visual acuity (BCVA), postoperative residual bed thickness, and postoperative endothelial cell count (ECC) were evaluated. Preoperative BCVA ranged from 1.3 to 1.0 LogMAR. Two eyes were pseudophakic and one eye had a traumatic cataract. Manual DALK was successfully accomplished in all three cases. The mean residual recipient bed thickness was 103 µm (range 68-130 µm). The mean endothelial cell loss at the 6th month of follow-up was 6% (range 3%-11%) with a further 1% decrease at 4 years. One of the patients underwent cataract surgery and limbal relaxing incisions 1 year after DALK having a total endothelial cell loss of 4.8% at 2 years of follow-up. BCVA at 2 years of follow-up was 0.1 LogMAR (range 0.22-0.0 LogMAR). No episode of rejection was recorded, and all grafts remained clear at last follow-up (5 years, range 4-6 years). Manual DALK should be considered in cases of corneal scars in optical zone resulting from penetrating wound.

Deep Anterior Lamellar Keratoplasty After Previous Anterior Lamellar Keratoplasty to Improve the Visual Outcomes.

To describe a series of patients who underwent deep anterior lamellar keratoplasty (DALK) after previous anterior lamellar keratoplasty (ALK) to improve their visual outcomes. This is a retrospective case series of 9 DALK eyes (9 patients) with a history of previous ALK and an unsatisfactory visual outcome. Surgery was performed in all cases at least 3 years after ALK. Cannula big bubble, air viscobubble, and manual dissection techniques were performed. Preoperative and postoperative best-corrected visual acuity, residual recipient bed thickness, and endothelial cell count were evaluated. Follow-up was at least 24 months for all eyes. Two subtotal anterior lamellar keratoplasties (through 1 type 1 big bubble and 1 air viscobubble) and 7 manual dissection DALKs were achieved. A small rupture of the residual recipient bed occurred during 1 case, and it was managed without penetrating keratoplasty conversion. Mean best-corrected visual acuity improved from 0.64 to 0.09 logMAR. Postoperative residual recipient central bed thickness was less than 80 μm in all cases. No postoperative complications were recorded at the last follow-up (24-36 months postoperatively). Different DALK techniques can be successfully used to improve visual acuity in previous ALK eyes with an unsatisfactory visual outcome.

Femtosecond laser-assisted (triple-)deep anterior lamellar keratoplasty with a novel liquid interface

Abstract Purpose Deep anterior lamellar keratoplasty (DALK) has become a safe and standardized technique for the treatment of corneal diseases. The use of femtosecond lasers for corneal trephination in DALK allows for a precise and controlled corneal trephination very close to Descemet’s membrane (DM) which is important for a successful pneumatic dissection and results in separation of Pre-Descemet’s layer (Dua’s layer, PDL) and/or DM from the stroma. However, even with newer curved contact interfaces the cornea becomes massively warped during trephination causing irregular trephination patterns which results in high postoperative astigmatism. Here we present a novel technique of Femto-DALK using a non-contact liquid interface where the cornea keeps its natural curvature during the complete laser process. Methods Case series of two patients, which underwent femtosecondlaser-assistant deep anterior lamellar keratoplasty by using a non-contact liquid interface. The laser device (Ziemer LDV Z8, Ziemer Ophthalmic Systems AG, Port, Switzerland) was used for trephination of the donor and recipient cornea. In one patient Femto-DALK was combined with femtolaser-assisted cataract surgery (Femto-Phaco). Read-out parameters were the feasibility of the technique and postoperative outcome. Results Trephination was successful in both cases leading to a circular trephination very close to the recipients’ Descemet’s membrane. In both patients a big bubble type 1 was induced successfully. Conclusions Femtosecondlaser-assisted DALK using a liquid interface is a novel procedure representing an alternative to manual DALK or Femto-DALK with a contact interface. Future studies need to evaluate outcomes and complication rates in comparison to manual DALK and microscope-integrated Optical Coherence Tomography-aided DALK.

Deep anterior lamellar keratoplasty techniques; predescemetic versus big bubble: Anterior segment optical coherence tomography study

To compare the visual and refractive outcomes and anterior segment optical coherence tomography (AS-OCT) findings of 2different deep anterior lamellar keratoplasty (DALK) techniques in the treatment of advanced keratoconus with and without successful big bubble formation. In this retrospective comparative case series, data from 79consecutive eyes of 69patients who underwent either big bubble (group 1, n: 62) or manual DALK (group 2, n: 17) were analyzed. The visual and refractive results, keratometric values and residual stromal thickness were assessed. Patients were seen at 1, 3, 6 and 12 months after the procedure and 1 month after complete suture removal. A big bubble was successfully obtained in 62eyes (78.5%; group 1) and manual dissection was performed in the 17remaining eyes (21.5%; group 2). The final best spectacle-corrected visual acuity (BSCVA) was 0.38 logMAR and 0.55 logMAR in Group 1 and 2, respectively (P<0.05). At the final visit, BSCVA≤0.30 logMAR was achieved in 80% and 60.8% of eyes in Groups 1 and 2, respectively (P<0.001). Groups 1 and 2 were comparable in terms of mean keratometry: 47.80D±2.81D (range, 41.30D to 54.2D) versus 45.90D±3.62D (range, 41.10D to 53.8 D), respectively; (P=0.56) and keratometric astigmatism: 3.81D± 2.1D (range, 1.0D to 6.20D) versus 3.56D±1.92D (range 1.2D to 6.85D), respectively; (P=0.40) at the final follow-up. The mean residual stromal thickness was 36.90±17.80μm in group 2. The presence of residual posterior corneal stroma when big bubble formation is not successfully achieved in DALK is correlated with lower postoperative visual acuity.

Clinical outcome after air-assisted manual deep anterior lamellar keratoplasty for fungal keratitis poorly responsive to medical treatment.

PurposeFungal keratitis remains an important disorder because of difficulty in its diagnosis, and some patients do not respond to medical treatment using antifungal local and systemic agents. This study was carried out to determine the therapeutic value of air-assisted manual therapeutic deep anterior lamellar keratoplasty (TDALK) in the treatment of fungal keratitis not curable by antifungal chemotherapy.MethodsSeventeen patients (18 eyes) who were referred to Fukuoka University Hospital and treated surgically from January 2006 to April 2018, in whom a diagnosis of fungal keratitis was confirmed by typical clinical findings and microbiological or histological analysis of corneal specimens, and who were poorly responsive to topical and systemic antifungal medication, whereas the lesion had not resulted in corneal perforation, were enrolled in this study and were treated by air-assisted manual TDALK. Clinical outcomes including treatment course, therapeutic success rate, visual acuity outcomes and graft clarity rate were analyzed.ResultsThe most common pathogen was Fusarium, followed by Candida and Aspergillus. Beneficial therapeutic results (a clear or translucent graft) were achieved in 15 of 18 eyes (83%). There was no recurrence of infection and resulting visual acuity ≤0.15 logarithm of minimal angle of resolution unit was achieved in 15 eyes (83%). Intraoperative microperforation of Descemet’s membrane (DM) was not observed in any patients.ConclusionAir-assisted manual TDALK can be effective for treating severe fungal keratitis. In addition, air-assisted manual TDALK might be an alternative procedure to big-bubble DALK, because it can provide ambulatory vision and can preserve potentiality of vision with less risk of intraoperative perforation of DM.

Evaluation of Big Bubble Technique for Deep Anterior Lamellar Keratoplasty in Patients With Radial Keratotomy.

To report the outcome of deep anterior lamellar keratoplasty (DALK) and success rates of the big-bubble (BB) technique or manual dissection after a failed use of the BB technique in eyes that underwent prior radial keratotomy (RK). A retrospective chart review of patients who underwent DALK after RK at Toronto Western Hospital, Canada, between 1999 and 2017 was performed. Demographic characteristics, success rates of the BB technique and manual dissection, intraoperative and postoperative complications, and best spectacle-corrected visual acuity before and after corneal transplant were analyzed. Ten eyes of 9 patients were included in the analysis. The average age was 64 ± 10 years (range 49-82). The average time between the RK surgery and the corneal transplant was 20 ± 5 years (range 8-24). Indications for corneal transplant were significant irregular astigmatism in 5 eyes (50%), central scarring or haze in 4 eyes (40%), and progressive hyperopia with visual fluctuation in one eye (10%). BB was successfully achieved in one eye (10%). In 6 eyes (60%), manual dissection was performed, and in 3 eyes (30%), DALK surgery was converted to penetrating keratoplasty. The average best spectacle-corrected visual acuity on the last follow-up visit was 0.26 ± 0.08 logMAR (Snellen equivalent 20/36). One eye that underwent manual DALK and one eye that underwent penetrating keratoplasty developed a rejection episode 4 and 2 months after keratoplasty, respectively. In both cases, rejection resolved with topical steroids. In eyes that underwent prior RK, DALK by manual dissection should be considered as a preferable surgical technique.

Comparaison des résultats anatomiques et fonctionnels à 12 mois d’une série de kératoplasties lamellaires profondes assistées au laser femtoseconde Z6 versus trépanation manuelle pour kératocônes sévères

The management of severe keratoconus requires corneal transplantation, for which the gold standard is deep anterior lamellar keratoplasty (DALK), preserving the healthy Descemet's membrane and endothelium. The safety and reproducibility of corneal cuts have been improved by the evolution of femtosecond lasers in refractive surgery, and femtosecond laser in DALK would seem to provide the same advantages over the manual method. In our retrospective study, we compare functional and anatomical results of femtosecond assisted DALK versus manual trephination DALK in patients with keratoconus in stage 4of the Krumeich classification. It is a retrospective study including all patients with stage 4keratoconus who underwent femtosecond laser assisted DALK between November 2012and November 2015in Nantes hospital. We compared those patients to a group of patients who underwent manual DALK in the same period, paired by age and maximal keratometry. We assessed visual acuity, pachymetry, endothelial cell density (specular microscopy), and keratometry before surgery and at 4, 8and 12months of follow-up. Laser settings and intraoperative complications were recorded. Nineteen patients underwent surgery by femtosecond assisted DALK, 6women and 12men with average age 30.2±10.8years at transplantation. They were paired with a group of 17patients who underwent manual DALK in order to compare results. Before surgery, mean visual acuity in the femtosecond group was 0.90logMAR versus 0.89logMAR in the manual group, showing no statistically significant difference (P=0.96). Both groups were similar in terms of preoperative age, mean keratometry, pachymetry and endothelial cell density. Average visual acuity post-surgery was 0.27, 0.26; and 0.14logMAR for femtosecond DALK versus 0.27, 0.17et 0.25for manual DALK at 4, 8and 12months follow-up, respectively showing no statistically significant difference. After surgery, at 4, 8and 12months, mean pachymetry was similar in both groups, and average endothelial cell density was 2390cells/mm2in femtoDALK versus 2531cells/mm2in manual DALK at 12months of follow-up, showing no statistically significant difference (P=0.5726). The rate of Descemet's membrane microperforations during the procedure was low and similar for both groups. Our study allows for a 12month follow-up, with assessment of visual recovery, anatomical result and endothelial safety in a sample of 19femtosecond laser assisted DALK with no statistical significant difference versus the manual trephination group. Femtosecond laser allows for increased reproducibility of the DALK procedure without reducing adverse effects during surgery. Femtosecond laser seems to improve the technique of the DALK procedure, and future developments could improve the reproducibility of DALK even further. A medical economics study would be necessary to determine the cost effectiveness of femtosecond laser assisted DALK.

Comparison of 12-month anatomic and functional results between Z6 femtosecond laser-assisted and manual trephination in deep anterior lamellar keratoplasty for advanced keratoconus

The management of severe keratoconus requires corneal transplantation, for which the gold standard is deep anterior lamellar keratoplasty (DALK), preserving the healthy Descemet's membrane and endothelium. The safety and reproducibility of corneal cuts have been improved by the evolution of femtosecond lasers in refractive surgery, and femtosecond laser in DALK would seem to provide the same advantages over the manual method. In our retrospective study, we compare functional and anatomical results of femtosecond-assisted DALK versus manual trephination DALK in patients with keratoconus in stage 4 of the Krumeich classification. It is a retrospective study including all patients with stage 4 keratoconus who underwent femtosecond laser-assisted DALK between November 2012 and November 2015 in Nantes university medical center. We compared those patients to a group of patients who underwent manual DALK in the same period, paired by age and maximal keratometry. We assessed visual acuity, pachymetry, endothelial cell density (specular microscopy), and keratometry before surgery and at 4, 8 and 12months of follow-up. Laser settings and intraoperative complications were recorded. Nineteen patients underwent surgery by femtosecond-assisted DALK, 6women and 12men with average age 30.2±10.8years at transplantation. They were paired with a group of 17patients who underwent manual DALK in order to compare results. Before surgery, mean visual acuity in the femtosecond group was 0.90logMAR versus 0.89logMAR in the manual group, showing no statistically significant difference (P=0.96). Both groups were similar in terms of preoperative age, mean keratometry, pachymetry and endothelial cell density. Average visual acuity post-surgery was 0.27; 0.26; and 0.14logMAR for femtosecond DALK versus 0.27; 0.17et 0.25 for manual DALK at 4, 8 and 12months follow-up respectively, showing no statistically significant difference. After surgery, at 4, 8 and 12months, mean pachymetry was similar in both groups, and average endothelial cell density was 2390cells/mm2 for femto DALK versus 2531cells/mm2 for manual DALK at 12months of follow-up, showing no statistically significant difference (P=0.5726). The rate of Descemet's membrane microperforations during the procedure was low and similar for both groups. Our study allows for a 12-month follow-up, with assessment of visual recovery, anatomic result and endothelial safety in a series of 19femtosecond laser-assisted DALK with no statistical significant difference versus the manual trephination group. Femtosecond laser allows for increased reproducibility of the DALK procedure without reducing adverse effects during surgery. Femtosecond laser seems to improve the technique of the DALK procedure, and future developments could improve the reproducibility of DALK even further. A medical economics study would be necessary to determine the cost-effectiveness of femtosecond laser-assisted DALK.

Wet-Peeling Technique of Deep Anterior Lamellar Keratoplasty With Hypotonic Water and Blunt Dissection for Healed Hydrops.

To describe the surgical technique and outcomes of "wet-peeling" deep anterior lamellar keratoplasty (DALK) using sterile water and blunt dissection in cases with corneal scarring after healed corneal hydrops. Manual DALK using a "wet-peeling" technique was performed in 20 eyes of 20 consecutive patients with healed corneal hydrops between June 2011 and October 2013. Intraoperative microperforations were encountered in 2 (10%) cases. None of the cases required conversion to penetrating keratoplasty. There was significant improvement in mean best-corrected visual acuity at the end of 24 months postoperatively (0.99 ± 0.30 logMAR vs. 0.20 ± 0.11 logMAR; P < 0.001). The postoperative mean residual stromal bed thickness was 48.9 ± 5.9 μm, and mean central corneal thickness was 557.2 ± 50.3 μm. The mean endothelial density was 2021 ± 236 cells/mm at the final follow-up. Manual DALK using sterile water can be successfully performed in corneas with healed hydrops. Favorable visual outcomes may be attributed to thin residual bed thickness postoperatively.

Factors Predicting Refractive Outcomes After Deep Anterior Lamellar Keratoplasty in Keratoconus

To determine the factors that predict refraction, mean keratometry, and keratometric astigmatism after deep anterior lamellar keratoplasty (DALK) in keratoconus. Consecutive interventional case series. This study enrolled 194 consecutive eyes of 181 patients with keratoconus who underwent DALK using the big-bubble technique. Indications for surgery included contact lens intolerance or poor corrected visual acuity. Univariate analyses and analysis of covariance were used to investigate recipient-, surgical-, and postoperative-related variables capable of predicting refractive outcomes, including mean keratometry, keratometric astigmatism, and spherical equivalent refraction. The mean patient age was 27.9 ± 8.2 years, and the patients were followed for 35.9 ± 18.2 months postoperatively. Preoperative mean keratometry (P = .007), time interval from surgery to running suture removal (P = .01), and suture-tract vascularization (P = .04) significantly influenced postoperative mean keratometry. Vitreous length predicted postoperative spherical equivalent (P = .03). Postoperative keratometric astigmatism failed to demonstrate any significant correlation with the preoperative, surgical, and postoperative variables. Postoperative refractive outcomes did not change relative to patient age and sex, central and peripheral corneal thickness, recipient trephination size, surgical technique (big-bubble vs manual dissection DALK), duration of steroid administration, and elevated intraocular pressure. Keratoconus patients with an elongated posterior segment and/or steep corneas should be informed of the need for postoperative optical correction after DALK. Running suture removal should be postponed for as long as possible if there is no suture-related complication.

Phenotypic Evaluation of Severely Damaged Ocular Surface after Reconstruction by Cultured Limbal Epithelial Cell Transplantation

Objective: To report the clinical outcome of autologous cultured limbal epithelial cell transplantation (CLECT) followed by deep anterior lamellar keratoplasty (DALK) in paediatric eyes and to correlate the clinical outcome with the phenotype of rejuvenated corneal epithelium. Methods: Four patients with total limbal stem cell deficiency (LSCD) underwent autologous CLECT. Cultivated cell sheets were transplanted onto the damaged ocular surface followed by DALK surgery. Excised corneal buttons were subjected to histopathological analysis. Data recorded included age, sex, laterality, nature of injury, follow-up period, severity of stem cell deficiency, visual acuity, Schirmer's test and impression cytology. Results: At a mean follow-up period of 19.5 ± 7.4 (range 9-26) months after CLECT, all 4 eyes showed epithelialized and clinically stabilized ocular surface. Manual DALK was performed in all 4 eyes, with a mean follow-up of 9.75 ± 4.5 (range 5-15) months. All eyes exhibited smooth and clear corneal epithelium with improved visual acuity. Excised corneal buttons demonstrated organized corneal epithelial morphology and showed expression of cornea-specific CK3/12 marker. Conclusion: Restoration of severely damaged ocular surface following chemical injury by using 2-stage meticulous approaches offers a new modality for the treatment of severe LSCD. Transplantation of cultivated autologous limbal epithelial cell sheet followed by DALK surgery can efficiently restore the corneal phenotype with improved vision.

Sweating of Descemet's membrane during deep anterior lamellar keratoplasty in absence of perforation

We report a case of spontaneous Descemet’s membrane sweating of aqueous humor during a manual deep anterior lamellar keratoplasty (DALK) without perforation of Descemet’s membrane. An 81-year-old female developed a neurotrophic central ulcer with descemetocele in the right eye, and her visual acuity was count fingers at 30 cm. She was unresponsive to medical treatment, and an uneventful manual DALK was performed. Six months after surgery, unaided visual acuity improved to 6/30. Seven months after surgery, the patient had a decrease in visual acuity to count fingers in the same eye. She was diagnosed as having corneal melting with a central descemetocele in the previous lamellar graft. A repeat manual DALK graft was performed. Lamellar dissection was performed starting from the edge of descemetocele, proceeding to the corneal periphery and maintaining the surgical plane of the previous DALK. During the surgical procedure, continuous and localized sweating of aqueous through Descemet’s membrane was observed in the area of the descemetocele. After drying of the recipient bed, no visible perforation of Descemet’s membrane was found. After removal of the previous DALK graft, a new stromal lamellar graft was sutured. The surgery was concluded without complications. One day after surgery, the graft was clear, with no detachment of Descemet’s membrane. If Descemet’s membrane sweating is observed during DALK and there is no visible perforation, the reason may be a hidden micron perforation in an intact Descemet’s membrane. It is recommended to continue with surgery maintaining maximum diligence and low intraocular pressure to prevent extension of micron perforation.

Deep Lamellar Keratoplasty After Resolution of Hydrops in Keratoconus

Deep anterior lamellar keratoplasty (DALK) using Anwar's big-bubble technique is contraindicated in cases of previous hydrops because of the risk of Descemet membrane (DM) rupture at the hydrops scar. Improved manual lamellar dissection techniques down to the deepest stromal layers now enable manual DALK surgery for previous hydrops with the possibility of obtaining good vision, as an alternative to conventional penetrating keratoplasty. Two retrospective case reports of manual DALK in patients with previous hydrops. A 12-year-old boy, with keratoconus and resolved hydrops in his left eye with deep stromal scarring, underwent bilateral manual DALK without baring of the DM. An intraoperative microperforation occurred in his left eye and was managed by intracameral injection of air to seal the perforation. Eleven months after his right DALK and 10 months after his left DALK, his right best spectacle-corrected visual acuity (BSCVA) was 20/20, and his left BSCVA was 20/25. The right cornea was clear, whereas the left cornea had minimal residual deep stromal scarring. Endothelial cell count by specular microscopy was 2611 cells per square millimeter in the right eye and 2193 cells per square millimeter in the left eye. A 28-year-old man, with keratoconus and resolved hydrops in his right eye with deep stromal scarring, underwent right manual DALK without baring of the DM. Nine months postoperatively, his right BSCVA was 20/30, and the graft was clear. Endothelial cell count by specular microscopy was 3148 cells per square millimeter in the right eye. DALK can be performed in patients with previous hydrops. A controlled deep manual dissection technique without baring the DM is advocated. Good final BSCVA can be achieved despite leaving a thin residual layer of the stroma unexcised.